Sofa



FIG. 1 is a three-quarter, front perspective view of a sofa embodying my new design;

FIG. 2 is a front perspective view thereof; and

FIG. 3 is a side perspective view thereof.

The side of the sofa not shown is a mirror image of the side shown while the rear is conventional in appearance. 

The ornamental design for a sofa, as shown and described. 